Outdoor air pollution
Outdoor air pollution can be created from manufactured sources such as vehicles (for example, cars, trucks, planes and boats), gas-powered tools and yard machinery, using chemicals (for example, paint, aerosol sprays), commercial burning, industrial plants and by natural events (for example, dust or methane from cattle). Major sources of outdoor air pollution include:
- gasoline engine exhaust
- diesel engine exhaust
- airborne emissions from industrial plants
- emissions from residential heating
- natural events such as forest fires
Diesel- and gasoline-powered engine exhaust contains many harmful substances, including particulate matter (fine particles), sulphur oxides, carbon monoxide, nitrogen oxides, volatile organic compounds (VOCs), benzene and polycyclic aromatic hydrocarbons (PAHs). Ground level ozone, another harmful substance, is formed from a combination of pollutants.
Air pollution in your community can be affected by:
- some types of local businesses
- local traffic patterns (vehicle type and traffic density)
- whether you live in an urban or rural location
- geography (for example, valleys versus plains)
- weather patterns (for example, wind direction)
Indoor air pollution
Air inside your home can also be polluted. Major sources of indoor air pollution include:
- second-hand smoke
- radon
- indoor burning of coal or wood
The International Agency for Research on Cancer (IARC) classifies types of air pollutants differently depending on their link with cancer. For example, radon and diesel engine exhaust are known cancer-causing substances while gasoline engine exhaust is a possible cancer-causing substance. Find out more about how cancer-causing substances are classified.
In addition to making existing lung disease and heart problems worse, air pollution can lead to lung cancer. Several research studies have found an association between lung cancer and outdoor air pollution. Research has also determined that radon gas in indoor air can lead to lung cancer. But smoking is still the biggest cause of lung cancer by far in Canada.